Lanthanum-modified tobermorite synthesized from fly ash for efficient phosphate removal.

Phosphate removal from water by lanthanum-modified tobermorite synthesized from fly ash (LTFA) with different lanthanum concentrations was studied. LTFA samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer‒Emmett‒Teller specific surface area analysis. The results showed that the LTFA samples were mainly composed of mesoporous tobermorite-11 Å, and LTFA1 with a lanthanum concentration of 0.15 M had a high specific surface area (83.82 m2/g) and pore volume (0.6778 cm3/g). The phosphate adsorption capacities of LTFA samples were highest at pH 3 and gradually decreased with increasing pH. The phosphate adsorption kinetics data on LTFA samples were most accurately described by the Elovich model. The adsorption isotherms were in the strongest agreement with the Temkin model, and LTFA1 showed the highest phosphate adsorption capacity (282.51 mg P/g), which was higher than that of most other lanthanum-modified adsorbents. LTFA1 presented highly selective adsorption of phosphate with other coexisting ions (HCO3-, Cl-, SO42-, and NO3-). In addition, phosphate was adsorbed onto LTFA samples by forming inner-sphere phosphate complexes and amorphous lanthanum phosphate. This study provides technical support for development of efficient fly ash-based phosphate adsorbents.

Health and ecological risk of heavy metals in agricultural soils related to Tungsten mining in Southern Jiangxi Province, China.

Background: Dayu County, a major tungsten producer in China, experiences severe heavy metal pollution. This study evaluated the pollution status, the accumulation characteristics in paddy rice, and the potential ecological risks of heavy metals in agricutural soils near tungsten mining areas of Dayu County. Furthermore, the impacts of soil properties on the accumulation of heavy metals in soil were explored. Methods: The geo-accumulation index (Igeo), the contamination factor (CF), and the pollution load index (PLI) were used to evaluate the pollution status of metals (As, Cd, Cu, Cr, Pb, Mo, W, and Zn) in soils. The ecological risk factor (RI) was used to assess the potential ecological risks of heavy metals in soil. The health risks and accumulation of heavy metals in paddy rice were evaluated using the health risk index and the translocation factor (TF), respectively. Pearson's correlation coefficient was used to discuss the influence of soil factors on heavy metal contents in soil. Results: The concentrations of metals exceeded the respective average background values for soils (As: 10.4, Cd: 0.10, Cu: 20.8, Cr: 48.0, Pb: 32.1, Mo: 0.30, W: 4.93, Zn: 69.0, mg/kg). The levels of As, Cd, Mo, and tungsten(W) exceeded the risk screening values for Chinese agricultural soil contamination and the Dutch standard. The mean concentrations of the eight tested heavy metals followed the order FJ-S > QL > FJ-N > HL > CJ-E > CJ-W, with a significant distribution throughout the Zhangjiang River basin. Heavy metals, especially Cd, were enriched in paddy rice. The Igeo and CF assessment indicated that the soil was moderately to heavily polluted by Mo, W and Cd, and the PLI assessment indicated the the sites of FJ-S and QL were extremely severely polluted due to the contribution of Cd, Mo and W. The RI results indicated that Cd posed the highest risk near tungsten mining areas. The non-carcinogenic and total carcinogenic risks were above the threshold values (non-carcinogenic risk by HQ > 1, carcinogenic risks by CR > 1 × 10-4 a-1) for As and Cd. Correlation analysis indicated that K2O, Na2O, and CaO are main factors affecting the accumulation and migration of heavy metals in soils and plants. Our findings reveal significant contamination of soils and crops with heavy metals, especially Cd, Mo, and W, near mining areas, highlighting serious health risks. This emphasizes the need for immediate remedial actions and the implementation of stringent environmental policies to safeguard health and the environment.

Controllable Pyridine N-Oxidation-Nucleophilic Dechlorination Process for Enhanced Dechlorination of Chloropyridines: The Cooperation of HCO4- and HO2.

Dechlorination of chloropyridines can eliminate their detrimental environmental effects. However, traditional dechlorination technology cannot efficiently break the C-Cl bond of chloropyridines, which is restricted by the uncontrollable nonselective species. Hence, we propose the carbonate species-activated hydrogen peroxide (carbonate species/H2O2) process wherein the selective oxidant (peroxymonocarbonate ion, HCO4-) and selective reductant (hydroperoxide anion, HO2-) controllably coexist by manipulation of reaction pH. Taking 2-chloropyridine (Cl-Py) as an example, HCO4- first induces Cl-Py into pyridine N-oxidation intermediates, which then suffer from the nucleophilic dechlorination by HO2-. The obtained dechlorination efficiencies in the carbonate species/H2O2 process (32.5-84.5%) based on the cooperation of HCO4- and HO2- are significantly higher than those in the HO2--mediated sodium hydroxide/hydrogen peroxide process (0-43.8%). Theoretical calculations confirm that pyridine N-oxidation of Cl-Py can effectively lower the energy barrier of the dechlorination process. Moreover, the carbonate species/H2O2 process exhibits superior anti-interference performance and low electric energy consumption. Furthermore, Cl-Py is completely detoxified via the carbonate species/H2O2 process. More importantly, the carbonate species/H2O2 process is applicable for efficient dehalogenation of halogenated pyridines and pyrazines. This work offers a simple and useful strategy to enhance the dehalogenation efficiency of halogenated organics and sheds new insights into the application of the carbonate species/H2O2 process in practical environmental remediation.

Selective anchoring of Pt NPs on covalent triazine-based frameworks via in situ derived bridging ligands for boosting photocatalytic hydrogen evolution.

The efficient and stable production of hydrogen (H2) through Pt-containing photocatalysts remains a great challenge. Herein, we develop an effective strategy to selectively and uniformly anchor Pt NPs (∼1.2 nm) on a covalent triazine-based framework photocatalyst via in situ derived bridging ligands. Compared to Pt/CTF-1, the obtained Pt/AT-CTF-1 exhibits a considerable photocatalytic H2 evolution rate of 562.9 µmol g-1 h-1 under visible light irradiation. Additionally, the strong interaction between the Pt NPs and in situ derived bridging ligands provides remarkable stability to Pt/AT-CTF-1. Experimental investigations and photo/chemical characterization reveal the synergy of the in situ derived bridging ligands in Pt/AT-CTF-1, which can selectively anchor the Pt NPs with homogeneous sizes and efficiently improve the transmission of charge carriers. This work provides a new perspective toward stabilizing ultrasmall nanoclusters and facilitating electron transfer in photocatalytic H2 evolution materials.

Sulfuric acid-assisted ball milling for the preparation of Si-O-enriched straw biochar: removal efficiency of rhodamine B and adsorption mechanism.

Traditional pyrolysis biochar has been widely employed to treat dye wastewater. However, there are some problems in the pyrolysis process, such as the generation of harmful gases and the low content of silico-oxygen functional groups to promote adsorption. Straw biochar (Ac-BCbm) was prepared by sulfuric acid co-ball milling method. The adsorption performance and adsorption mechanism of rhodamine B (RhB) under different preparation conditions and factors were investigated. The results showed that the adsorption rate of Ac-BCbm on RhB was up to 94.9%, which was 60.5% and 55.8% higher than that of ball-milling straw (STbm) and biochar prepared by pyrolysis (STBC600), respectively. The Ac-BCbm had better adaptability under different pH and common interfering ions for remove RhB. Characterization and DFT simulation analysis revealed that the sulfuric acid co-ball milling process promoted the formation of Si-OH and Si-O-CH3 oxygen-containing functional groups of Si component in straw, which enhanced the hydrogen bonding interactions and effectively improved the adsorption efficiency. This study investigated a new strategy for biochar preparation by sulfuric acid co-ball milling, which provides an additional development direction for the efficient resource utilization of straw.

Chemical composition, sources, and health risks of PM2.5 in small cities with different urbanization during 2020 Chinese Spring Festival.

To investigate the impact of quarantine measures and fireworks banning policy on chemical composition and sources of PM2.5 and associated health risks in small, less developed cities, we sampled in Guigang (GG), Shaoyang (SY), and Tianshui (TS), located in eastern, central, and north-western China, in 2020 Spring Festival (CSF). Mass concentration, carbonaceous, metals, and WSIIs of PM2.5 were analyzed. The study found high levels of PM2.5 pollution with the average concentration of 168.05 µg/m3 in TS, 134.59 µg/m3 in SY, and 125.71 µg/m3 in GG. A negative correlation was found between the urbanization level and PM2.5 pollution. Lockdown measures reduced PM2.5 mass and industrial elements. In non-control period (NCP), combustion and fireworks were the major sources of PM2.5 in GG and TS, and industry source accounted for a significant proportion in the relatively more urbanized SY. Whereas on control period (CP), soil dust, combustion, and road dust were the main source in GG, secondary aerosols dominated in SY and TS. Our health risk assessment showed unacceptable levels of non-carcinogenic and carcinogenic risks over the study areas, despite lockdown measures reducing health risks. As and Cr(VI), as the major pollutants, their associated sources, industry sources, and fireworks sources, posed the greatest risk to people at the sampling sites after exposure to PM2.5. This work supports the improvement of PM2.5 control strategies in small Chinese cities during the CSF.

Analyzing the phosphorus flow characteristics in the largest freshwater lake (Poyang Lake) watershed of China from 1950 to 2020 through a bottom-up approach of watershed-scale phosphorus substance flow model.

Understanding the historical patterns of phosphorus (P) cycling is essential for sustainable P management and eutrophication mitigation in watersheds. Currently, there is a lack of long-term watershed-scale models that analyze the flow of P substances and quantify the socioeconomic patterns of P flow. This study adopted a watershed perspective and incorporated crucial economic and social subsystems related to P production, consumption, and emissions throughout the entire life cycle. Based on this approach, a bottom-up watershed P flow analysis model was developed to quantify the P cycle for the first time in the Poyang Lake watershed from 1950 to 2020 and to explore the driving factors that influence its strength by analyzing multi-year P flow results. In general, the P cycle in the Poyang Lake watershed was no longer a naturally dominated cycle but significantly influenced by human activities during the flow dynamics between 1950 and 2015. Agricultural intensification and expansion of large-scale livestock farming continue to enhance the P flow in the study area. Fertilizer P inputs from cultivation account for approximately 60% of the total inputs to farming systems, but phosphate fertilizer utilization continues to decline. Feed P inputs have continued to increase since 2007. The expansion of large-scale farming and the demand for urbanization are the main factors leading to changes in feed P input patterns. The P utilization rate for livestock farming (PUEa) is progressively higher than international levels, with PUEa increasing from 0.64% (1950) to 9.7% (2020). Additionally, per capita food P consumption in the watershed increased from 0.67 kg to 0.80 kg between 1950 and 2020. The anthropogenic P emissions have increased from 1.67 × 104 t (1950) to 8.73 × 104 t (2020), with an average annual growth rate of 2.41%. Watershed-wide P pollution emissions have increased by more than five-fold. Population growth and agricultural development are important drivers of structural changes in P flows in the study area, and they induce changes in social conditions, including agricultural production, dietary structure, and consumption levels, further dominating the cyclic patterns of P use, discharge, and recycling. This study provides a broader and applicable P flow model to measure the characteristics of the P cycle throughout the watershed social system as well as provides methodological support and policy insights for large lakes in rapidly developing areas or countries to easily present P flow structures and sustainably manage P resources.

Pollution and health risk assessment of rare earth elements in Citrus sinensis growing soil in mining area of southern China.

Background: Analyzing the pollution and health risk of rare earth elements (REEs) in crop-growing soils around rare earth deposits can facilitate the improvement of REE mining-influenced area. In this study, pollution status, fraction and anomaly, plant accumulation characteristics, and potential risks of REEs (including heavy and light rare earth elements, HREEs and LREEs) in C. sinensis planting soil near ion-adsorption deposits in southern Ganzhou were analyzed. The influence of the soil environment on REEs in soil and fruit of C. sinensis was also explored. Methods: The geo-accumulation index (Igeo) and ecological risk index(RI) were used to analyze the pollution potential and ecological risks of REEs in soils, respectively. Health risk index and translocation factor (TF) were applied to analyze the accumulation and health risks of REEs in fruit of C. sinensis. The influence of soil factors on REEs in soil and fruit of C. sinensis were determined via correlation and redundancy analysis. Results: Comparison with background values and assessment of Igeo and RI indicated that the soil was polluted by REEs, albeit at varying degrees. Fractionation between LREEs and HREEs occurred, along with significant positive Ce anomaly and negative Eu anomaly. With TF values < 1, our results suggest that C. sinensis has a weak ability to accumulate REEs in its fruit. The concentrations of REEs in fruit differed between LREEs and HREEs, with content of HREE in fruit ordered as Jiading > Anxi > Wuyang and of LREE in fruit higher in Wuyang. Correlation and redundancy analysis indicated that K2O, Fe2O3 and TOC are important soil factors influencing REE accumulation by C. sinensis, with K2O positively related and Fe2O3 and TOC negatively related to the accumulation process.

Mechanochemically synthesized silicotungsten acidified ZVI composite for persulfate activation: Enhancement of the electron transfer and Fe slowly release mechanism.

Zero-valent iron (ZVI) is a promising technology for groundwater treatment, and its efficiency primarily depends on the electron transfer. However, there are still some problems such as low electron efficiency of ZVI particles and high yield of iron sludge that limits the performance, which warrant further investigation. In our study, a silicotungsten acidified ZVI composite (m-WZVI) was synthesized by ball milling to activate PS to degrade phenol. m-WZVI has a better performance on phenol degradation (with a removal rate of 91.82%) than ball mill ZVI(m-ZVI) with persulfate (PS) (with a removal rate of 59.37%). Compared with m-ZVI, the first-order kinetic constant (kobs) of m-WZVI/PS is 2-3 times higher than that of the others. Iron ion was gradually leached in m-WZVI/PS system, being only 2.11 mg/L after 30 min, having to avoid excessive consumption of active substances. The underlying mechanisms of m-WZVI for PS activation mainly include: 1) were elucidated through different characterizations analyses that accounted for silictungstic acid (STA) can be combined with ZVI, and a new electron donor (SiW124-) was obtained, which improved the transfer rate performance of electrons for activating PS; 2) singlet oxygen (1O2) is the main active substance for phenol degradation, but other radicals also played an important role. Therefore, m-WZVI has good prospects for improving the electron utilization of ZVI.

Strategy for cost-effective BMPs of non-point source pollution in the small agricultural watershed of Poyang Lake: A case study of the Zhuxi River.

In recent years, Poyang Lake has been affected by severe agricultural non-point source (NPS) pollution, a global water pollution problem. The most recognized and effective control measure for agricultural NPS pollution is the strategic selection and placement of best management practices (BMPs) for critical source areas (CSAs). The present study employed the Soil and Water Assessment Tool (SWAT) model to identify CSAs and evaluate the effectiveness of different BMPs in reducing agricultural NPS pollutants in the typical sub-watersheds of the Poyang Lake watershed. The model performed well and satisfactorily in simulating the streamflow and sediment yield at the outlet of the Zhuxi River watershed. The results indicated that urbanization-oriented development strategies and the Grain for Green program (returning the grain plots to forestry) had certain effects on the land-use structure. The proportion of cropland in the study area decreased from 61.45% (2010) to 7.48% (2018) in response to the Grain for Green program, which was mainly converted to forest land (58.7%) and settlements (36.8%). Land-use type changes alter the occurrence of runoff and sediment, which further affect the nitrogen (N) and phosphorus (P) loads since sediment load intensity is a key factor affecting the P load intensity. Vegetation buffer strips (VBSs) proved the most effective BMPs for NPS pollutant reduction, and the cost of 5-m VBSs proved the lowest. The effectiveness of each BMP in reducing N/P load ranked as follows: VBS > grassed river channels (GRC) > 20% fertilizer reduction (FR20) > no-tillage (NT) > 10% fertilizer reduction (FR10). All combined BMPs had higher N and P removal efficiencies than the individual measures. We recommend combining FR20 and VBS-5m or NT and VBS-5m, which could achieve nearly 60% pollutant removal. Depending on the site conditions, the choice between FR20+VBS and NT + VBS is flexible for targeted implementation. Our findings may contribute to the effective implementation of BMPs in the Poyang Lake watershed and provide theoretical support and practical guidance for agricultural authorities to perform and direct agricultural NPS pollution prevention and control.

Role of phosphite in the environmental phosphorus cycle.

In modern geochemistry, phosphorus (P) is considered synonymous with phosphate (Pi) because Pi controls the growth of organisms as a limiting nutrient in many ecosystems. The researchers therefore realised that a complete P cycle is essential. Limited by thermodynamic barriers, P was long believed to be incapable of redox reactions, and the role of the redox cycle of reduced P in the global P cycling system was thus not ascertained. Nevertheless, the phosphite (Phi) form of P is widely present in various environments and participates in the global P redox cycle. Herein, global quantitative evidences of Phi are enumerated and the early origin and modern biotic/abiotic sources of Phi are elaborated. Further, the Phi-based redox pathway for P reduction is analysed and global multienvironmental Phi redox cycle processes are proposed on the basis of this pathway. The possible role of Phi in controlling algae in eutrophic lakes and its ecological benefits to plants are proposed. In this manner, the important role of Phi in the P redox cycle and global P cycle is systematically and comprehensively identified and confirmed. This work will provide scientific guidance for the future production and use of Phi products and arouse attention and interest on clarifying the role of Phi in the environmental phosphorus cycle.

Targeted Decomplexation of Metal Complexes for Efficient Metal Recovery by Ozone/Percarbonate.

Traditional methods cannot efficiently recover Cu from Cu(II)-EDTA wastewater and encounter the formation of secondary contaminants. In this study, an ozone/percarbonate (O3/SPC) process was proposed to efficiently decomplex Cu(II)-EDTA and simultaneously recover Cu. The results demonstrate that the O3/SPC process achieves 100% recovery of Cu with the corresponding kobs value of 0.103 min-1 compared with the typical •OH-based O3/H2O2 process (81.2%, 0.042 min-1). The carbonate radical anion (CO3•-) is generated from the O3/SPC process and carries out the targeted attack of amino groups of Cu(II)-EDTA for decarboxylation and deamination processes, resulting in successive cleavage of Cu-O and Cu-N bonds. In comparison, the •OH-based O3/H2O2 process is predominantly responsible for the breakage of Cu-O bonds via decarboxylation and formic acid removal. Moreover, the released Cu(II) can be transformed into stable copper precipitates by employing an endogenous precipitant (CO32-), accompanied by toxic-free byproducts in the O3/SPC process. More importantly, the O3/SPC process exhibits excellent metal recovery in the treatment of real copper electroplating wastewater and other metal-EDTA complexes. This study provides a promising technology and opens a new avenue for the efficient decomplexation of metal-organic complexes with simultaneous recovery of valuable metal resources.

Preparation of amino-functionalized fly ash based tobermorite for enhanced removal of Cr(VI).

Amino-functionalized fly ash based tobermorite (NH2-FAT) was prepared via a two-step process including a hydrothermal preparation of fly ash based tobermorite (FAT) from fly ash (FA) and the impregnation of 3-aminopropyltriethoxysilane (APTES). The characteristics of FA, FAT, and NH2-FAT were systematically measured. The removal capacity of Cr(VI) by FAT and NH2-FAT were comparatively studied. The results indicated that the NH2-FAT presented excellent removal efficiency towards Cr(VI) in the condition of pH of 2. The adsorption capacity of Cr(VI) by NH2-FAT in this study was up to 498.39 mg/g resulted from Langmuir model, which was more superior to that of FAT, other reported FA based adsorbents and most amino-functionalized adsorbents. Furthermore, the removal mechanisms of Cr(VI) by NH2-FAT were ascribed to both electrostatic attraction and reduction to Cr(III) by amino groups. Overall, this work indicates the NH2-FAT is a promising adsorbent for treating wastewater containing Cr(VI), and provides a new utilization method of FA.

High Fe and Mn groundwater in the Nanchang, Poyang Lake Basin of China: hydrochemical characteristics and genesis mechanisms.

Based on the water quality test data of 257 groups of phreatic groundwater and 165 groups of confined groundwater in the Nanchang area and the redox conditions, acid-base conditions and the organic matter content in groundwater, we identified hydrochemical characteristics and genesis of groundwater with high Fe and Mn contents in Nanchang. The results showed that Fe and Mn exceeded the standard in both phreatic and confined groundwater. The over-standard rates of Fe and Mn in groundwater were 8.56-11.52% and 33.07-36.36%, respectively. The degree of pollution Fe and Mn in the confined groundwater is higher than that in the phreatic groundwater, and the degree of pollution caused by Mn is higher than that caused by Fe. The high Fe and Mn contents in groundwater were caused by the release of Fe and Mn minerals from the native environment due to changes in the groundwater environment of the study area. A mild redox environment (Eh < 100) and low pH value are favorable for Fe and Mn enrichment in groundwater. The presence of organic matter accelerates microbial activity and promotes the release of Fe and Mn from aquifer sediments. Therefore, the change in the native environment played an important role in the increase in Fe and Mn content in the study area.

Overcoming Electrostatic Interaction via Strong Complexation for Highly Selective Reduction of CN- into N2.

Limited by the electrostatic interaction, the oxidation reaction of cations at the anode and the reduction reaction of anions at the cathode in the electrocatalytic system nearly cannot be achieved. This study proposes a novel strategy to overcome electrostatic interaction via strong complexation, realizing the electrocatalytic reduction of cyanide (CN- ) at the cathode and then converting the generated reduction products into nitrogen (N2 ) at the anode. Theoretical calculations and experimental results confirm that the polarization of the transition metal oxide cathodes under the electric field causes the strong chemisorption between CN- and cathode, inducing the preferential enrichment of CN- to the cathode. CN- is hydrogenated by atomic hydrogen at the cathode to methylamine/ammonia, which are further oxidized into N2 by free chlorine derived from the anode. This paper provides a new idea for realizing the unconventional and unrealizable reactions in the electrocatalytic system.

Multifunctional porous ß-cyclodextrin polymer for water purification.

Keeping water clean is of vital significance for human health and environmental protection. In order to remove organic micro-pollutants and natural organic substances in water bodies and kill pathogenic microorganisms simultaneously, this study synthesized a multifunctional porous ß-cyclodextrin polymer with a high specific surface area by introducing quaternary ammonium groups and rigid benzene rings, respectively, which was then polymerized with crosslinking agent-4,4'-bis (chloromethyl)-1,1'-biphenyl (BCMBP) in an ionic liquid system. The grafting of quaternary ammonium groups was beneficial for the removal of negative-charged humic acid (HA) and sterilization. The introduction of numerous rigid structures during benzylation and Friedel-Crafts alkylation reaction could significantly improve the porosity and specific surface area of the polymer, conducive to the exposure of cyclodextrin binding sites and contaminant adsorption. By changing the proportions of quaternization and benzylation, the structure and surface properties of the polymer could be adjusted, thus further regulating the adsorption performance. Compared with activated carbon, the polymer named BQCD-BP with a huge surface area of 1133 m2 g-1 prepared under optimized conditions showed outstanding adsorption performance and sterilization ability. The pseudo-second-order kinetic constant of BQCD-BP reached 1.2058 g·mg-1·min-1, which was approximately 50 times greater than that of activated carbon (0.0256 g·mg-1·min-1) under the same experimental condition. The adsorption capacity of BQCD-BP to HA was twice as high as that to AC, and the antibacterial ability of BQCD-BP was significant, achieving 90% at the dosage of 1g L-1. Moreover, the adsorption process was hardly affected by the hydrochemical conditions, and the polymer was easy to regenerate. In addition, the excellent adsorption and antibacterial performance of the polymer were also identified by natural water treatment. COD was almost completely removed, and the removal efficiency of TP reached 92% after contact with BQCD-BP. The sterilization rate of BQCD-BP to viable bacteria in complex water bodies reached 82%. Undoubtedly, BQCD-BP is a potential multifunctional water treatment material with reasonable design in the actual water purification.

Elucidating the role of confinement and shielding effect over zeolite enveloped Ru catalysts for propane low temperature degradation.

Volatile organic compounds (VOCs) are the main precursor for ozone formation and hazardous to human health. Light alkane as one of the typical VOCs is difficult to degrade to CO2 and H2O by catalytic degradation method due to its strong C-H bond. Herein, a series of ultrafine Ru nanoclusters (<0.95 nm) enveloped in silicalite-1 (S-1) zeolite catalysts were designed and prepared by a simple one-pot method and applied for catalytic degradation of propane. The results demonstrate that the enveloped Ru1@S-1 catalyst has excellent propane degradation performance. Its T95 is as low as 294 °C with moisture, and the turnover frequency (TOF) value is up to 5.07 × 10-3 s-1, evidently higher than that of the comparison supported catalyst (Ru1/S-1). Importantly, Ru1@S-1 exhibits superior thermal stability, water resistance and recyclability, which should be attributed to the confinement and shielding effect of the S-1 shell. The in-situ DRIFTS result reveals that the propane degradation over Ru1@S-1 follows the Mars-van-Krevelen (MvK) mechanism, where the hydroxy from the framework of zeolite can provide the active oxygen species. Our work provides a new candidate and guideline for an efficient and stable catalyst for the low-temperature degradation of the light alkane VOCs.

Validation and application of diffusive gradient in thin-film (DGT) equipped novel cyclodextrin polymer gels for monitoring endocrine disrupting chemicals (EDCs) and environmental risk assessment in the Taihu lake basin.

Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17ß-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68 × 10-6, 3.38 × 10-6, 3.34 × 10-6 and 4.31 × 10-6 cm2/s) and to test the performance of DGT, such as adsorption capacity and deployment time (1-5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3-9 of pH, 0.001-0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0-20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.

Degradation of pesticide wastewater with simultaneous resource recovery via ozonation coupled with anaerobic biochemical technology.

The effective treatment of pesticide wastewater with high organic content, complex composition and high-toxicity has attracted enormous attention of researchers. This work proposes a new idea for removing the pesticide wastewater with simultaneous resource recovery, which is different from the traditional view of mineralization of pesticide wastewater via composite technology. This novel strategy involved a sequential three-step treatment: (a) acidic Ozonation process, to remove the venomous aromatic heterocyclic compounds; (b) hydrolysis and ozonation in alkaline conditions, enhancing the biodegradability of pesticide wastewater, mainly due to the dehalogenation, elimination of C=C bonds and production of low molecular-weight carboxylate anions; (c) the final step is anaerobic biological reactions. Based on the characterizations, this two-stage acidic-alkaline ozonation can efficiently degraded the virulence of pesticide wastewater and enhance its biodegradability from 0.08 to 0.32. The final anaerobic biochemical treatment can stably remove the residuals and convert the low molecular-weight organics into CH4, achieving the resource recovery. This work explored the pH-dependent of ozonized degradation of pesticide wastewater and gives a new perspective of wastewater treatment.

Multiple hydrolyses of rice straw by domesticated paddy soil microbes for methane production via liquid anaerobic digestion.

The aim of this study was to investigate the hydrolysis of rice straw (RS) using domesticated paddy soil microbes (DPSMs) with swine wastewater (SW) as the nitrogen source and the multiple hydrolyses for CH4 production via liquid anaerobic digestion (L-AD). Three hydrolyses of RS with a 45% inoculation ratio (IR) under the conditions of a carbon/nitrogen ratio (C/N ratio) of 40, temperature of 37 °C, inoculum/substrate ratio (I/S ratio) of 2:1, and immersion depth of 6.0 cm were optimal, attaining maximum volatile fatty acids (VFAs) after five days, possibly owing to the synergistic effect of aerobic microbes (Firmicutes and Actinomycetes) and anaerobic microbes (Bacteroidetes and Acidobacteria). After three hydrolyses, the degradation rates of hemicellulose, cellulose, and lignin in RS were 88.45%, 83.19% and 70.09%, respectively. The accumulative CH4 production reached 462.11 mL/g VS after three hydrolyses, and its curve fitted well with the modified Gompertz model (R2 > 0.984).